Method of operating furnaces



June 14, 1932. 1 DE FLOREZ 1,862,737

METHOD OF OPERATING FURNACES Original Filed Oct. 29, 1926 3 Sheets-Sheetl Nw I, I HU i mm. ww

June 14, 1932. DE FLQREZ 1,862,737

METHOD 0F OPERATING FURNAGES Original Filed Oct. 29, 1926 3 Sheets-Sheet2 .lune 14, 1932. L. DE FLoREz METHOD OF OPERATING FURNACES OriginalFiled Oct. 29, 1926 3 Sheets-Sheet I new and improved type of heater, ma

bustion efficiency.

Patented June 14, 1932 UNITED STATES PATENT OFFICE LUIS DE FLOREZ, 0FPOMFRET, CONNECTICUT, .AS-SIGNOR TO m TEXAS COMPANY, .L

CORPORATION OF DELAWARE i METHOD OF OPERATING FURNAOIB riginalapplication illed ctober 29, 1926, Serial No. 145,054. Divided and thisapplication filed November 3, 1928. Serial No. 317,088.

This invention relates to improvements in heaters for fluids and moreparticularly to those comprising heating surfaces of the tublar type. Myinvention, which comprisesba e used for any duties to which this class oapparatus may be put and is particularly adapted for use Where a fluidis to be heated progressively and fuel burned with high com- Theinvention further relates to a method of effecting a heat treatment ofpetroleum oils.

This application is a division of my coending application Serial No.145,054, filed ctober 29, 1926.

The operation of the heater is not limited to the use of an specifictype of fuel. In fact one of the o jects of my invention is to provide acombustion chamber which can be readily adapted to burn a wide varietyof fuels with relatively little alteration.

My invention is to some extent an elaboration of and an improvement uponthe invention shown in m co-pending application, Serial No. 120,06 nowU. S. Patent 1,717,- 334, filed July 2, 1926, and the general objectsand advantages set forth in said co-pending application are generallyapplicable to the present invention. However, the structure illustratedand described in this application has many important oints of differencefrom that disclosed in sai copending application, which oints ofdifference I shall describe more ully hereafter in the specification.These points of difference result in greatly simplifying, cheapening andimproving the construction shown by said copending application, andinproducing a heater peculiarly adapted to exacting conditions ofoperation.

As important structural features to be covered by this application I mayrefer to a structure which takes full advantage of the self-supportingarch principle of construction and circular sections whereby acomparatively small amount of steel may be made to perform itsstructural requirement; the fact that the furnace is adapted to theburning of as, oil or powdered fuel; the method used o supporting thetubular heating surface solely from their upper ends, thus permittingfree expansion, ease of removal; simple access for cleaning orreplacement' the safety of the apparatus in the event of explosions orbursting of tubes and other important advantages of construction willappear from the drawings and following description.

The general design of the heater is such as to permit the use of bothradiant and convection heat in substantially separate stages. Thus I amenabled to apply heat in the convection stage from gases which have beenrelieved of a considerable quantity of heat thus to avoid overloadingthese surfaces and eliminate the corresponding detrimental effect.Furthermore rovision is made t0 begin the absorption o the heatgenerated b the fuel immediately after ignition whic permits thereduction of the combustion space, while the surfaces which are Withinvlew of the flame can operate at a. high transfer rate thus reducing thetotal surface required for a given capacity.

I shall describe an embodiment of my construction as a vertical pipestill adapted to heat petroleum or its products having a verticalcylindrical heating chamber around the inner wall of which the tubes orpipes are disposed, said heating chamber being centrally fired from thetop or bottom.

In the preferred construction illustrated I have shown the furnace asfired from the top. The location of the burner or other means b whichfuel is introduced into the combustlon chamber is such that the flametends to remain parallel to the tubes and out of direct contacttherewith, thus avoiding any substantial transfer of heat b convection.In the case of the apparatus red from the top, the outlet at the bottomof the heating chamber discharges into a flue in which an ash pit isprovided in the event that powdered fuel is to be burned. Both theburner chamber and the outlet are of less diameter than the heatingchamber and extend beyond thc same so that the ends of the tubes mayproject outside of the heating chamber, entirely out of contact with thehot gases. The products of combustion may pass from the flue to aneconomizer section in which the hot gases come into direct contact witha. series of tubes in which the fluid to be heated is given apreliminary heating. From the economizer the products of combustion thenpass to the stack. A by-pass around the economizer connecting theradiant heat section of the furnace with the stack is controlled by anexplosion damper adapted to be opened automatically by the forcel of anexplosion in the furnace, or by hand 1n case of a leak or failure of atube. I have also illustrated a modification of the invention in whichthe transfer of heat is practically entirely accomplished by radiationand the economizer section is replaced by an air preheater which has forits purpose to preheat the air required for combustion thus permitting ahigher flame temperature at the exit of the burner and making itpossible to transfer additional heat at high temperature which wouldhave to be transferred by contact at low temperatures if no air preeater were used.

It will he understood that the heater is applicable to a wide variety ofuses such as the generation of steam, heating the gases, etc. and Itherefore do not desire to be confined to any particular use orconstruction beyond that set forth in the appended claims.

ln the accompanying drawings, in which like reference numerals denotelike parts throughout the several views thereof:

Figure 1-is a vertical longitudinal section of a pipe still constructedin accordance with my invention;

Figure 2-is a horizontal section taken on the line 2--2 of Figure 1;

Figure 3-is a detail plan view of a portion of the upper tube sheet;

Figure 4-is a detail plan view of a portion of the lower tube sheet; and

Figure 5-is an elevation partially in section of a modified form of myinvention.

Referring more particularly to the drawings, a steel shell 10 preferablyc lindrical in form is supported at its base by s iort posts or columns11 which are suitably secured in a foundation 12. An annular iiange 13is secured to the lower edge of the shell 10 and supports the weight ofthe heat insulatin lining 14 and the inner refractory lining 1. A steelcylindrical ring 16 of somewhat less diameter than the shell 10 isdisposed below the shell 10 and supported upon the foundation 12 bymeans of a lower flange 17 secured thereto; an upper outwardly extendingHarige 18 is secured to the upper edge of the ring 16 and is disposed insubstantially the same horizontal plane as the Harige 13 on the shell10. The ring 16 encircles the outlet 19 for the products of combustion.

The upper edge of the shell 10 supports the upper tube sheet 20 which isprovided with an integral depending flange 21 at its outer edge and anintegral upwardly extending flange 22 at its inner ed e. The tube sheet20 is preferably formed o a. plurality of segmental sections, one ofwhich is illustrated in Figure 3. The depending flange 2l is secureddirectly to the shell 10 and the flange 22 is secured to a rin 23 towhich is also secured the framewor 24 which su ports the burner cone 25of the furnace. '1 e upper ends of the bars comprising the framework 24are secured to a ring 26 which supports the centrally located burnercasing.

It will be noted that by this construction the metal shell 10 supportspractically the entire weight of the furnace structure, and that theupper tube sheet 2O together with the ring 23, the framework 24 and thering 26 form, in effect, a self supporting arch, the stresses of whichare transmitted to and borne directly by the shell 10. Inasmuch as thisshell is cylindrical and takes the greater portion of the strainedgewise, it is apparent that a large factor of safety may be securedwith the use of a comparatively small amount of steel work. It is to beunderstood, of course, that the shell 10 need not be a single piece ofmetal, and that other equivalent supporting means might be employed,such as for example, a squirrel cage construction comprising Wide bandsof metal at the top and bottom of the furnace rigidly joined together byvertical bars. The word shell therefore as used in the claims, isintended to include such adaptations and modifications.

The oil heating tubes 27 are inserted in apertures in the upper tubesheet 20 and are connected together by couplings 28 having shoulderswhich rest upon the upper tube sheet 20 so that the tubes are suspendedvertically therefrom. The tubes 27 are disposed adjacent the innerrefractory wall 15,

etween the same and the products of combastion in the center of thefurnace. The lower ends of the tubes extend through apertures in a lowertube sheet 29 which consists of a plurality of flat segments restingupon the. flanges 13 and 18, and are provided with 'couplings 30, bothof these sets of couplings having plugs 31 in their ends which may beremoved to permit access to the tubes for cleaning.

The burner cone 25 of the furnace is substantially conical in shape andflares out- Wardly at its bottom forming a horizontal shoulder 32. Theupper narrow end of the burner cone 25 is provided with an opening 83 inwhich is inserted a suitable burner 34, the exact construction of whichis not illustrated but which may be of any well known type suitable forthe particular fuel to be burned. The outlet 19 is provided with anoutwardly flaring rounded shoulder 35. Both the burner cone 25 and theoutlet 19 are centrally disposed with respect to the tubes and for thisreason the hot products of combustion tend to tlow through the center ofthe furnace away from direct contact with the tubes 27 and to transmitheat thereto mainly by radiation, the shoulders 32 and 35 serving tomaintain a blanket of dead or relatively slow movin gases in the neihborhood oi the tubes. it will also be note that the couplings 28 and 30joinin the tubes together are disposed outside o the furnace where theyare not subjected to the destructive effect of the direct heat of thefurnace. The upper ends of the tubes are enclosed in a protectingchamber 36, the top of which is removable to permit access to the tubesfor cleaning or replacement.

By this construction of the tubes it will be observed that they aresupported solely from' the upper tube sheet, and inasmuch as theirexpansion is mainly in the direction of their length, they may expandfreely without damage to themselves or to their supports. It will benoted also that the tubes are so positioned that ready access may be hadto their ends. Thus the lower wall of the heating chamber cooperateswith the outlet 19 and the foundation 12 to form an annular recess inwhich the lower ends of the tubes are located and the usual tools may bereadily inserted into this recess to expand the ends of the tubes intothe couplings 30 when new tubes are inserted. The segmental constructionof the upper and lower tube sheets, together with the fact that thelower tube sheet merely rests upon the flanges 13 and 18, enables theentire section of the tubes to be lifted by a suitable crane ifnecessary, to permit small repairs to be made to the furnace lining.When inserting new tubes it is merely necessary to cut the old tubes atconvenient places, remove the ends from the couplings, lower a new tubeinto place and expand its end into the coupling with the usual tool forthis purpose having rotating rollers.

The outlet 19 of the furnace is connected to an underground flue 40 andan ash pit 41 having a steam ejector 42 for removing the ash is locatedimmediately beneath the outlet 19 and the burner 34. The steam ejectoris protected by a fluid cooled grate 43 through which the oil to beheated may be pumped. Provision is thus made for easily and effectivelyremoving the ash when powdered coal or other fuel having considerablesolid residue is burned. A manhole 44 having a cover 45 permits accessto the ash pit 41, flue 40, and the interior of the furnace.

The fiue 40 connects with an economizer section 50 of conventionalconstruction in which the oil may be preheated in tubes in directcontact with the flue gases.

The flue gases after passing through the economizer section 50 passthrough a flue 51 into a stack 52 and are controlled by a damper 53located in the iue 51. The stack 52 also communicates directly with theflue 40 so that the economizer section 50 ma be bypassed by opening thedamper 54. e construction of the damper 54 is such that it will beopened automatically by any explosion in the still or by any other causecreating sudden dangerous pressure of the flue gases so that a quickescape for the products of combustion is provided.

The damper 54 com rises a rotatable shaft 55 mounted in the stac 52 andprovided with an external operating handle 56 for hand operation. Acollar 57 is rigidl, secured to the shaft 55 within the stack an isconnected by means of a pivoted link 58 with the damper 54. The lowerend of the damper 54 is provided with a bearing 59 which co-operateswith an axis suitably located to cause the damper 54 to pivot about thebearing 59.

A platform having a railing 66 encircles the upper end of the furnaceand is supported by the shell 10.

Referring to the modification shown.` in Figure 5 the construction ofthe furnace and stack is similar to that shown in Fi res 1 and 2, butthe economizer section is eliminated and its place is taken by an airpreheater of the recuperator type disposed directly' in the flue 40. Noexplosion damper is shown in this ligure, but one might easily bearranged by constructing a by-pass around the air heater 70 and placingits explosion damper in the by-pass.

The use of the air preheater shown in this modification permits the useof substantially the theoretical quantity of air for complete -100combustion of the fuel and enables a considerably higher flametemperature to be secured in the heating chamber than has been possibleheretofore in other types of furnaces and therefore more radiant heatwill 105 be transferred to the heating tubes 27 in this chamber. Theadditional radiant heat transfer thus secured makes it possible toeconomically eliminate the economizer section 50 shown in Figure 1.

What I claim is:

1. The method of quickly raising hydrocarbon oils to a high temperature,comprising burning a fuel to create a source of intensive radiant heatand impelling the dame and the 115 products of combustion in a verticalunobstructed path, passing the oil in a series of vertical parallelpaths, all of said paths being in substantially uniformradiativerelationtothe source of heat and parallel to the path of the120 flame and products of combustion, to quickly absorb such heat andreduce the temperature of the combustion gases, withdrawing the gaseswhile maintaining them in substantially non-convective relation to saidpaths, and 125 passing the gases in convective relation to the airemployed for combustion to preheat the same.

2. The method of heatin hydrocarbon oils to a high temperature whiccomprises burn- 130 4 means? ing a fuel to create a source of intensiveheat and impelling the {iame and the products of combustion in avertical unobstructed path passing the hydrocarbon oil in a. series ofparallel paths, all of said paths being in substantially uniformradiative relation to the source of heat, to quickly absorb such heatand reduce the temperature of the combustion gases, withdrawing thegases While maintaining them in non-convective relation to said paths,and passing the gases in convective relation to the air employed forcombustion to preheat the same.

3. The method of quickly raising oil to a desired temperature, whichcomprises burning a fuel to create a flame as a source of intensiveradiant heat and impelling the flame and the products of combustion in avertical unobstructed path, passing the oil in radiative relation to theflame and the hot combustion products serially through vertical pathswhich are parallel to the path of the ame and products of combustion andsubstantially equidistant therefrom, to quickly absorb radiant heat andreduce the temperature of the products of combustion, While maintainingthe products of combustion in substan tially non-convective relation tosaid paths, passmg the products of combustion in convective relation tothe air employed to preheat the same and supplying to the burning fuelsubstantially the theoretical quantity of air necessary for completecombustion of the fuel.

In Witness whereof I have hereunto set my hand this 31st day of October1928.

- LUIS DE FLOREZ.

CERTIFICATE 0F CORRECTION.

Patent No. l, 862, 737.

LUIS de FLREZ.

June 14, 1932.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows:

Page l, lines 3 and`4,

for "tublar" read tubular; page 4, line 5, claim 6, before "parallel"insert the word vertical, and line 7, after "heat" first occurrenceinsert the words and parallel to the path of the flame and products ofcombustion; and that the said Letters Patent should be read with thesecorrections therein that the same may conformto the record of the casein the Patent Office.

Signed and sealed this 4th day of October, A. D. 1932.

(Seal) M. J. Moore, Acting Commissioner of Patents.

4 means? ing a fuel to create a source of intensive heat and impellingthe {iame and the products of combustion in a vertical unobstructed pathpassing the hydrocarbon oil in a. series of parallel paths, all of saidpaths being in substantially uniform radiative relation to the source ofheat, to quickly absorb such heat and reduce the temperature of thecombustion gases, withdrawing the gases While maintaining them innon-convective relation to said paths, and passing the gases inconvective relation to the air employed for combustion to preheat thesame.

3. The method of quickly raising oil to a desired temperature, whichcomprises burning a fuel to create a flame as a source of intensiveradiant heat and impelling the flame and the products of combustion in avertical unobstructed path, passing the oil in radiative relation to theflame and the hot combustion products serially through vertical pathswhich are parallel to the path of the ame and products of combustion andsubstantially equidistant therefrom, to quickly absorb radiant heat andreduce the temperature of the products of combustion, While maintainingthe products of combustion in substan tially non-convective relation tosaid paths, passmg the products of combustion in convective relation tothe air employed to preheat the same and supplying to the burning fuelsubstantially the theoretical quantity of air necessary for completecombustion of the fuel.

In Witness whereof I have hereunto set my hand this 31st day of October1928.

- LUIS DE FLOREZ.

CERTIFICATE 0F CORRECTION.

Patent No. l, 862, 737.

LUIS de FLREZ.

June 14, 1932.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows:

Page l, lines 3 and`4,

for "tublar" read tubular; page 4, line 5, claim 6, before "parallel"insert the word vertical, and line 7, after "heat" first occurrenceinsert the words and parallel to the path of the flame and products ofcombustion; and that the said Letters Patent should be read with thesecorrections therein that the same may conformto the record of the casein the Patent Office.

Signed and sealed this 4th day of October, A. D. 1932.

(Seal) M. J. Moore, Acting Commissioner of Patents.

5 CERTIFICATE OF CORRECTION.

Patent No. 1,862,737. June 14, 1932.

LUIS de FLOREZ.

It is hereby certified that in Certificate of Correction issued October4, 1932, in the above numbered patent, the claim 6, in line 3, shouldread claim 2; and that the said Certificate of Correction shouldbe readwith this correction therein that the same may conform to the record ofthe case in the Patent Office.

Signed and sealed this 8th day of November, A. D. 1932.

M. J. Moore,

(Seal) Acting Commissioner of Patents.

